Investigating the Factors of Increasing the Efficiency of Heterojunction Quantum Dot Solar Cell

Document Type : Research Paper

Authors

Faculty of Electrical and Computer Engineering, University of Sistan and Baluchestan, P.O. Box 9816745563, Zahedan, Iran

Abstract

Factors affecting on heterojunction quantum dot solar cell’s efficiency includethickness of wide band transparent semiconductor and quantum dot layers, doping level of quantum dots layer and the type of metal used as anode. This paper represents a simulation of a structure consisting of a layer of short ligand coated PbS quantum dots and a layer of ZnO semiconductor and gold anode using COMSOL Multiphysics v5.4 x64. The primary model had 2.62% efficiency for a cell with a Schottky contact between anode and quantum dot layer and 7.95% efficiency for a cell with an ohmic contact. A sweep in doping level of quantum dots layer for 1015, 1016 and 1017 cm-3 led to 7%, 7.95% and 5.2% for ohmic contact and 2.6%, 2.62% and 2.2% for schottky contact, respectively. A sweep in thickness of PbS quantum dot layer from 50nm to 100nm resulted in an advance in cell’s efficiency from 2.1% to 2.91% for a cell with a schottky contact and from 7% to 8.12% for a cell with an ohmic contact, as a conclusion to increasing the depletion region’s length, hence an increase in electric field in the junction area. In addition, ZnO layer’s thickness from 70nm to 150nm showed a decrease in efficiency from 9.4% to 6% due to limitation of exciton’s diffusion length. These excitons are recombined before being harvested by anode and cathode.

Keywords

References

 [1] Amoli, Salar, Hossein et al. construction of Cds/ CdSe Quantom Dots Solar Cell and Increasing their Efficiency Using Mn2+Ions, Nanomeghyas,2, 75-82, 2014 (in Persian).
[2] Wu, Zhiang, M. Wang, Zhiming, Quantum Dot Solar Cells, Springer New York Heidelberg Dordrecht London, 2014.
[3] Navid Mohammad Sadeghi Jahed, Heterojunction Quantum Dot Solar Cells, PhD Thesis, University of Waterloo, 2016.
[4] Shen, Qing, et al. Characterization of hot carrier cooling and multiple exciton generation dynamics in PbS QDs using an improved transient grating technique, Journal of Energy Chemistry, 24, 712-716, 2015.
[5] Koole, Rolf, et al. Size effects on Semiconductor Nanoparticles, Nanoparticles, 2, 13-51, 2014.
[6] Song, Jung Hoon, Jeong, Sohee, Colloidal quantum dot solar cells: from material to devices, Nano Convergence, 4, 1-8, 2017.
[7] Aqoma, Havid, et al. Simultaneous Improvement of Charge Generation and Extraction in Colloidal Quantum Dot Photovoltaics Through Optical Management, Advanced Functional Material, 25, 6241-6249, 2015.
[8] Pan, Zhenxiao, et al, Quantum dot-sensitized solar cells, Chemical Society Reviews, 47, 7659-7702, 2018.
[9] Sanehira, M. Erin, et al. Enhanced mobility CsPbI3 quantum dot arrays for record-efficiency, high-voltage photovoltaic cells, Science Advances, 3, eaao4204, 2017.
[10] Carey, Graham H, Colloidal Quantum dot solar cells, Chem. Rev., 115, 12732–12763, 2015.
[11] Johnston, K. W, et al. Schottky-quantum dot photovoltaics for efficient infrared power conversion, Applied Physics Letters, 92, 151115, 2008.
[12] Luther, M. Joseph, et al. Stability Assessment on a 3% Bilayer PbS/ZnO Quantum Dot Heterojunction Solar Cell, Advanced Material, 22, 3704-3707, 2010.
[13] Eisner, Flurin, et al.  Solution-Processed In2O3/ZnO Heterojunction Electron Transport Layers for Efficient Organic Bulk Heterojunction and Inorganic Colloidal Quantum-Dot Solar Cells, Solar RRL, 2, 1800076, 2018.
[14] D. Aaron, et al. Depleted Bulk Heterojunction Colloidal Quantum Dot Photovoltaics, Advanced Materials, 23, 3134-3139, 2011.
[15] Wilis, Shawn M, et al. The Transitional Heterojunction Behavior of PbS/ZnO Colloidal Quantum Dot Solar Cells, Nano Lett, 12, 1522−1526, 2012.
[16] Gao, Jinbao, et al. Quantum Dot Size Dependent J-V Characteristics in Heterojunction ZnO/PbS Quantum Dot Solar Cells, Nano Lett, 11, 1002–1008, 2011.
[17] Hu, Lomg, et al. Achieving high-performance PbS quantum dot solar cells by improving hole extraction through Ag doping, Nano Energy, 46, 212-219, 2018.

Files

History

  • Receive Date: 31 January 2019
  • Revise Date: 13 May 2019
  • Accept Date: 07 February 2020

Share

How to cite

Statistics